Developers are stepping back from BlackBerry because they say creating apps is too complex and costly for the size of the market. RIM’s devices have different screens sizes, varied operating systems and several ways to navigate, from a physical keyboard to touchscreen to a scroll button. In deploying Apple applications, there are very few surprises . . . In Android, there are increasingly more surprises. But in BlackBerry, there are immediately lots of gotchas across the board.

The article linked here is misleading in one big aspect by comparing the ease of development and number of apps for the Playbook - mere months after its launch - against the iOS devices (I think 5 years since the iPhone was launched)and the Android devices (I think 2 years since first launched). It might be worthwhile to look at developers comments and number of apps in the first 6 months after the first iOS and Android devices were introduced. I would not be surprised if the situation was similar to that currently existing for the Playbook.

One obvious challenge with RIM's Playbook is that the device interfaces with the user in a dramatically different way compared to their BlackBerrys. And this makes things more complicated - for now. At some point in time, there will be developers who have mastered sufficiently the differences to surf through them irrespective of the nature of the apps being coded - and are willing to share the how-to tips with others.

One main advantage of the iPad is that its user interface is the same as that of its conceptual predecessor, the iPhone/iPod Touch, albeit over a bigger screen area. I don't know much about the Android devices.

One idea - could there be a "common" API between all these devices that one could use? Hence, a developer could "code once" and "deploy for all"?

>One idea - could there be a "common" API between all these devices that one could use? Hence, a developer could "code once" and "deploy for all"?

Of course not.
Apps would have to be tailored to the lowest common denominator.
The app would have to adapt to the poorest sound capability of the 3, with the poorest graphics of the three, fit to run on the slowest processor of the three, etc. And on top of all that: accommodate for all different interaction models. In short: a bad idea.